Phosphine imide

In chemistry a phosphine imide (sometimes abbreviated to phosphinimide) also known as a iminophosphorane is a functional group with the formula R₃P=NR. While structurally related to phosphine oxide its chemistry has more in common with phosphonium ylides.

Triphenylphosphine phenylimide is a simple commercially available phosphine imide where all R-groups are phenyls

Anions of this group, with the structure R₃P=N⁻, are called phosphinoimidates and are used as ligands to form phosphinimide complexes which are highly active catalysts in some olefin polymerization reactions.^[1]

Synthesis

Phosphine imides can be isolated as intermediates in the Staudinger reaction and have also been prepared by the action of hydroxylamine-O-sulfonic acid on phosphines, proceeding via a p-aminophosphonium salt.^[2]

Reactions and applications

The functional group will readily hydrolyse to give a phosphine oxide and an amine

R₃P=NR' + H₂O → R₃P=O + R'NH₂

Phosphinimide ligands of the general formula NPR₃⁻ form transition metal phosphinimide complexeses. Some of these complexes are potential catalysts for the synthesis of polyethylene.^[1]

See also

• Aminophosphine
• Phosphazene